S-unno - With S-unno, you can make phone calls to any fixed or mobile number in more than 200 countries at absolutely low rates. Rates start from as low as US 2cents/minute. S-unno uses your 3G or WiFi connection to place these calls so that you can start saving now. Download is Free, Sign-up is Free! Remember NO subscriptions either! Not just phone calls, S-unno offers much more – SMS, Value-added Services and an extensive list of features, which are up and coming, are available to you at no additional subscription charges. S-unno is available for PCs too – use your S-unno account to make calls from PC or your mobile phone. Calls between S-unno users are Free wherever you are. Get your friends on S-unno and start making free calls!

FreejeFreeje itís an application for cheap international calls from mobile phone which is great for tourists, people living abroad and people who need to call abroad

JabberTurn your Android into an IP Phone with Cisco Jabber for Android. IMPORTANT: Cisco Jabber for Android requires an account with your company's Cisco Unified Communications ManagerTM and will not work without it

MobileVOIPWith MobileVoip you can make free* voip calls from your mobile phone

Cheap Calls - XonXar AppXonxar finds the cheapest rates amongst many VOIP providers and allows you to use them without subscribing with those